Fix DNS composite_eval.py always raising TypeError (eval_composite missing sample_rate) - #3079

Running recipes/DNS/enhancement/composite_eval.py as a script fails
immediately with TypeError: eval_composite() missing 1 required positional argument: 'sample_rate'.

The DNS copy of eval_composite takes three arguments (composite_eval.py:19):

def eval_composite(ref_wav, deg_wav, sample_rate):

sample_rate is genuinely required — it is forwarded to wss(), llr() and
SSNR() inside the function body. But the __main__ block at
composite_eval.py:459 still calls it with two:

clean_sig = librosa.load(clean_path_f, sr=None)[0]
enhanced_sig = librosa.load(enhanced_path_f, sr=None)[0]
res = eval_composite(clean_sig, enhanced_sig)

Why the intended fix is unambiguous

The same recipe already contains a correct call —
recipes/DNS/enhancement/train.py:462:

composite_metrics = eval_composite(
    clean.squeeze().cpu().numpy(),
    predictions[0].squeeze().cpu().numpy(),
    self.hparams.sample_rate,
)

And recipes/Voicebank/MTL/ASR_enhance/composite_eval.py still carries the
pre-change shape this file was copied from — a two-parameter
def eval_composite(ref_wav, deg_wav) with a matching two-argument call at
:435. So the DNS copy gained the sample_rate parameter, train.py was
updated, and this script's __main__ block was not.

The change

librosa.load(..., sr=None) already loads at the file's native sample rate and
returns it as the second element — the script was discarding it with [0].
This PR keeps that value and passes it through, so the metrics are computed at
the rate the audio is actually stored at rather than at a hardcoded guess:

clean_sig, sample_rate = librosa.load(clean_path_f, sr=None)
enhanced_sig = librosa.load(enhanced_path_f, sr=None)[0]
res = eval_composite(clean_sig, enhanced_sig, sample_rate)

Checked with the pinned ruff v0.12.4 from .pre-commit-config.yaml, run from
the repository root: ruff format --check reports 1 file already formatted
and ruff check reports All checks passed!

🤖 Generated with Claude Code